Portable computers are now well known, of which the so-called "laptop" computer is an example. The laptop computer generally has a substantially parallelopiped outer form, with a tilt-up display screen, and is of a weight and size making it very easy to carry and use on one's lap. A small version of the portable computer is commonly designated as a "notebook" personal computer, typically weighing about six pounds. Such portable computers, while being very effective for specific purposes, are generally somewhat limited in the computer capabilities which they can provide, particularly because of their small size, and because of their relatively low permissible power drain, in view of the fact that they must be battery operated.
To retain the useful physical size characteristics of a small portable computer while it is being used as such, while expanding its capabilities when it is at a home base, it is known to provide an expansion base on which the portable computer can be placed and to which it can be electrically interconnected. The expansion base typically contains suitable power supply electronics for supplying power to the adjacent portable computer and also carries electronic equipment such as additional memory, provision for additional optional cards, modem equipment, etc. to expand the computer capabilities of the portable. To permit this electronic expansion, typically the portable is provided at its rear vertical surface with a multi-pin connector, and a mating connector is provided on the expansion base so that the two connectors can be mated by sliding the laptop horizontally toward the expansion base connector until the two connectors mate.
Some drawbacks exists with such known forms of systems. First, the external monitor which is connected to the portable computer when in use on the expansion base has typically been placed beside the laptop computer, or on a special shelf or suspension system nearby. In general, it could not be placed upon the top of the laptop because the relatively great weight of a typical monitor cannot safely be supported on the relatively flimsy end fragile top of the closed portable computer.
Furthermore, it is relatively difficult to remove the laptop computer from its position on the usual expansion base because of the substantial forces required to disconnect the multi-contact connector interconnecting the portable computer and the expansion base. This connector may typically have up to nearly two hundred pins and corresponding sockets, and a separating force of as much as about twenty-five pounds may be required. While it is feasible to place a handle on the laptop computer to aid one in forcing the laptop to disconnect from the expansion base, this procedure is rather awkward and requires application of substantial force.
Another typical drawback of such assemblies is that it is often somewhat difficult to provide the alignment necessary to slide the portable onto the expansion base so accurately that the pins and sockets of the respective connectors mate exactly, and do not become misaligned by a small amount which may nevertheless cause damage to the connector system and make assembly difficult.
A further drawback is that if the portable computer is merely placed on top of the expansion base and the two connectors mated, there is opportunity during the assembly or disassembly process of placing further undesirable strains on the connectors due to misalignment or cocking of the portable computer sideways, or even tilting upwardly during assembly or disassembly. Either of these occurrences may make assembling the laptop on the base more difficult, or result in some damage, such as bending of the connector pins.
A typical desktop expansion base of the prior art is that designated for use with the Compaq Model LTE 286/20, sold by Compaq Computer Corporation of Houston, Tex., which provides for the support of a laptop computer on an expansion base by sliding the laptop horizontally along the top of the expansion base until the multi-connector plug of the laptop mates with the multi-connector plug of the expansion base, the expansion base then providing a variety of desirable auxiliary electronic functions for use in connection with, and as an extension of, the laptop computer. However, this latter system has no provision for support of an external monitor, requires substantial force to disassemble the laptop connector from the expansion base connector, and can present some difficulty in assuring that the laptop moves or slides exactly horizontally and normally to the expansion base connector during assembly so that the pins and sockets of the two connectors mate easily and precisely.
It is therefore an object of the present invention to provide a new and useful expansion base and expansion base system for receiving a portable computer on the top of an expansion base and connecting them together electrically so as to provide auxiliary electrical functions for the portable computer so long as it remains in its position on the expansion base.
It is also an object to provide such an expansion base and system which provide for support of an external monitor in a manner to conserve space in the work area.
Another object is to provide such a system in which the force which the operator must apply to disengage the connectors of the expansion base and of the portable computer from each other is greatly reduced.
Still another object is to provide such a system in which the portable computer is accurately guided while it is being slid into position, so that precise, proper mating of the connector of the portable computer and the connector of the expansion base is automatically accomplished.